Apparatus for washing oils with an immiscible wash liquid



Nov. 28, 1950 c. E. AYRES 2,531,547 APPARATUS FOR WASHING OILS WITH AN IMMISCIBLE WASH LIQUID Filed Sept. 9, 1946 WASHED OIL WASH LIQUID 7 IN VEN TOR. C. E. AYRES ATTOR N EYS Patented Nov. 28, 1950 UNITED STATES PATENT OFFICE APPARATUS FOR. WASHING OILS WITH AN IMMISCIBLE WASH LIQUID Charles E. Ayres, Phillips, Tex, assignor to Phillips Petroleum Company, a corporation of Delaware 3 Claims. 1

This invention relates to the treatment of oils. In one of its more specific aspects it relates to the treatment of oils by washing with liquids immiscible with the oils, such as water and apparatus therefor.

Water washes are frequently used in various hydrocarbon oi1 treating processes to remove chemical salts, unreacted and partially reacted acids or alkalis carried in solution or in suspension in the oil. Such washin operations are frequently performed in tanks containing the wash water and equipped with perforated distribution spiders.

The object of the perforated spider is to disperse the incoming oil into many small streams which, in passing up through the water, expedite contacting between the water and oil. These perforations are ordinarily small in consideration of the volume of oil to be distributed so as to obtain a jet effect and thereby more efiicient washing. However, in many instances I have found that due to the high oil concentration at the perforations solid salts are often deposited on or in the orifices resulting in a restriction or even stoppage of flow.

An object of my invention is to provide means for the prevention of orifice pluggin in such oil-water washing operations.

Another object of my invention is to provide an apparatus for use in combination with a distribution spider to prevent plugging of the spider orifices.

Still another and more specific object of my invention is to provide means to assist in preventing the precipitation of salts in wash tank distribution spiders at points of contact between oil and water.

Still other objects and advantages of my invention will be apparent to those skilled in the art from a careful study of the following description and attached drawing which respectively describes and illustrates a preferred embodiment of my invention.

Figure 1 is a diagrammatic illustration of one form of my oil-water washing apparatus. Figure 2 is a diagrammatic sectional view of my je suction washing apparatus.

Referring now to the drawing an elongated cylindrical tank Il may be horizontally disposed and. adapted to carry several pipe connections as a connection 12 for the introduction of oil to be water washed, a connection l3 for removal of washed oil and a connection It carrying a valve I5 for the introduction and removal of wash water.

However, such a Wash tank need not be horizontally disposed as illustrated, but may be vertically disposed, in which case the tank may substantially stand "on end. And further, the tank may be any other shape or form, providing it is 2 adapted to such a 2-liquid phase Washing operaion.

The inlet pipe 12 extends through the tank wall and nearly to the bottom. At its lower extremity is a T i5 adapted to carry two side arms ll. These arms or pipes ll have perforations 18 along the bottom sides as shown. This structure so far described constitutes a form of oil-water washing apparatus of the prior art. I have found that in using such a Water wash apparatus the openings IS in many cases acquire salt deposits which'restrict liquid flow therethrough, and after prolonged operation many of the openings may become plugged or substantially so. Under such conditions an oil transfer pump will have to operate at a markedly higher pressure in order to pump oil to be washed at a given rate through the wash spider.

I have found that by inserting a constricting orifice or jet l9 and providing openings 2B in each of the arms ll of the spider that salt precipie tation at the orifices 18 was substantially eliminated.

Each jet I9 may be of conventional jet construction, or may be such a piece of apparatus as a reducing swedge. When a swedge is used as a jet producing means, the body of the swedge must be adapted for installation in such a pipe, as pipe I? and the pipe-swedge assembly then attached to the T Hi. In such an assembly a swedge may be selected such that it will slide into the pipe in which it is to serve as a jet. The small end is inserted first, and the swedge pushed in sufliciently far that heat from welding at weld 2| may not interfere with threads 22. Threads 22 are for connecting the spider arm pipes ll to the T I6.

The openings 20 may preferably have been made in the pipes l1 prior to the installation of the swedge or jet members [9. These openings may be located with respect to the constricted end of the jet members 89 approximately as indicated in the drawing. operation of my device that upon passage of liquid through the constricted end of the jet memher a second liquid will be drawn in through the openings 20. This structure may also be brought of as a venturi type assembly.

Operation In the operation of my apparatus for washing one liquid with a second liquid wherein an insoluble precipitate forms in perforations of the spider arm orifices, the tank I l may be about halt filled with a wash liquid, for example, water. The liquid to be washed enters through the inlet pipe l2, flows through the jets i9 and finally leaves the spider arms through the perforations It. In passing through a jet l9, suction is created and wash liquid enters the pipe I! through the openings 20.

It is intended in the The openings 20 are intended to permit relatively large volumes of wash liquid to enter so that the relative volume of oil passing through the openings I8 is small, that is, the ratio of the volumesof oil to wash liquid is small. In this manner precipitation of insoluble matter at openings 18 isheld to a minimum or substantially eliminated;

Example In the sweetening of sour hydrocarbon oils by contacting with an aqueous cupric chlorid solution, the copper chloride treated oilis given an. after wash with an aqueous sodium sulfide solution. It has been found advantageous in some instances to follow this sulfide wash with a water wash. When using a water wash apparatus consisting of a tank partly filled with wash water and containing a distribution spider as hereinbefore described, I have found that many of the orifices in the distributor arms became partly or entirely plugged with deposited salts. After-prolonged operation so many orifices became restricted in effective area that the oil pump pressure had to be increased to a prohibitive pressure in order to pass the daily throughput of oil.

When pump pressuresreached a certain value, the washing step was bypassed, and the spider arms removed and the openings cleaned of the scale deposits. During this cleaning operation oil was passed from the sodium sulfide washing unit through a heat exchanger and into a fractionation unit and deposition of scale in thehea't exchanger and reboiler coils of the fractionator occurred. Such scale deposition on heat exchange surfaces adversely influences heat exchange and obviously is to be avoided.

In a gasoline sweetening operation followed by sulfide and water washes, I installed my jet- 19'- orifice 2i} assembly in each of the distribution scale deposits. During this cleaning operation substantially no orifice (i8) plugging had occurred by deposition of scale.

In this installation the water wash tankwas a horizontally disposed tank 10 feet in diameter by 36 feet long. The spiders (pipes II were 6' inch pipes having inch perforations along the bottom. Two such pipes were connected to a T at the endof the oil inlet pipe. The jets were 1 /2 inch in diameter and six openings (20) surrounded each jet. The gasoline so washed" in this unit was 600,000 gallons per day.

As mentioned hereinbefore, the water wash tank need not be of the form and disposition as illustrated in the drawing, but may be vertically disposed if desired. The tank may also be of a pan type, that is, a cylindrical tankof relatively large diameter and short axial length. In this latter case there may be four spider (ll) pipes, or a manifold system, all depending on the size of the tank and on capacity requirements.

Materials of construction will be determined by the products and reagents handled.

It will be obvious to those skilled in the art that many variations and. alterations in my washing apparatus may be made and yet remain within the intended spirit and scope of my invention.

Having disclosed my invention, I claim:

1. Apparatus for washing oils with an immiscible wash liquid comprising, in combination, a container for holding a wash liquid, an oil inlet pipe extending into said container, a perforated oil distribution spider positioned at the bottom portion of said container, means including a conduit having a tapered portion mounted within said spider for passing oil from said inlet pipe through the perforated portion of Said spider, said spider having an opening adjacent the reduced portion of said conduit whereby a flow of oil through said conduit causes washliquid 'to enterthe spider through said opening, the wash liquid in said spider preventing precipitation of insoluble matter at the periorationsin said spider.

2. Apparatus for washing oils withan immiscible wash liquid comprising, in combination, a container for holding a wash liquid, a perforated conduit positioned in the lower portion of said container, means for introducing oilinto said conduit including a jet supported within the conduit and having a portion ofreduced diameter. said conduit having an opening adjacent said portion of reduced diameter whereby flow of oil through said jet means causes wash liquid to flow through said opening by'venturi action, the wash liquid in said conduit preventing the deposition of solid matter at the perforated portions of said conduit.

3. Apparatus for washing oils with an immiscible wash liquid comprising, in combination, a tank adapted to contain a wash liquid, an oil distribution conduit in the lower portion of said tank, said conduit having a series of circumferem tia-lly disposed openings adjacent one end thereof and a series of perforations spaced from said openings and of relatively small size as compared with said openings, a jet inserted in said end-of the conduit having an outlet portion for directing oil into the perforated part ofsaid'conduit,

said jet having a portion of reduced diameter adjacent said openings, and means for delivering oil to the inlet portion of said jet.

CHARLES E. AYRES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 613,728 Shively NOV. 8, 1898 1,372,880 Hills Mar. 29, 1921 1,566,008 Hinrichs Dec. 15, 1.925 1,770,736 Funk July 15, 1930 1,992,133 Tarte Feb. 19} 1935 Certificate of Correction Patent No. 2,531,547 November 28, 1950 CHARLES E. AYRES It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 47, for the Word brought read thought; column 3, line 40, strike out scale deposits. During this cleaning and insert instead arms 17', and after a 30-day period of;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 6th day of March, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

